1 /*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "Interpolator.h"
18
19 #include <cmath>
20 #include <cutils/log.h>
21
22 #include "utils/MathUtils.h"
23
24 namespace android {
25 namespace uirenderer {
26
createDefaultInterpolator()27 Interpolator* Interpolator::createDefaultInterpolator() {
28 return new AccelerateDecelerateInterpolator();
29 }
30
interpolate(float input)31 float AccelerateDecelerateInterpolator::interpolate(float input) {
32 return (float)(cosf((input + 1) * M_PI) / 2.0f) + 0.5f;
33 }
34
interpolate(float input)35 float AccelerateInterpolator::interpolate(float input) {
36 if (mFactor == 1.0f) {
37 return input * input;
38 } else {
39 return pow(input, mDoubleFactor);
40 }
41 }
42
interpolate(float t)43 float AnticipateInterpolator::interpolate(float t) {
44 return t * t * ((mTension + 1) * t - mTension);
45 }
46
a(float t,float s)47 static float a(float t, float s) {
48 return t * t * ((s + 1) * t - s);
49 }
50
o(float t,float s)51 static float o(float t, float s) {
52 return t * t * ((s + 1) * t + s);
53 }
54
interpolate(float t)55 float AnticipateOvershootInterpolator::interpolate(float t) {
56 if (t < 0.5f) return 0.5f * a(t * 2.0f, mTension);
57 else return 0.5f * (o(t * 2.0f - 2.0f, mTension) + 2.0f);
58 }
59
bounce(float t)60 static float bounce(float t) {
61 return t * t * 8.0f;
62 }
63
interpolate(float t)64 float BounceInterpolator::interpolate(float t) {
65 t *= 1.1226f;
66 if (t < 0.3535f) return bounce(t);
67 else if (t < 0.7408f) return bounce(t - 0.54719f) + 0.7f;
68 else if (t < 0.9644f) return bounce(t - 0.8526f) + 0.9f;
69 else return bounce(t - 1.0435f) + 0.95f;
70 }
71
interpolate(float input)72 float CycleInterpolator::interpolate(float input) {
73 return sinf(2 * mCycles * M_PI * input);
74 }
75
interpolate(float input)76 float DecelerateInterpolator::interpolate(float input) {
77 float result;
78 if (mFactor == 1.0f) {
79 result = 1.0f - (1.0f - input) * (1.0f - input);
80 } else {
81 result = 1.0f - pow((1.0f - input), 2 * mFactor);
82 }
83 return result;
84 }
85
interpolate(float t)86 float OvershootInterpolator::interpolate(float t) {
87 t -= 1.0f;
88 return t * t * ((mTension + 1) * t + mTension) + 1.0f;
89 }
90
LUTInterpolator(float * values,size_t size)91 LUTInterpolator::LUTInterpolator(float* values, size_t size)
92 : mValues(values)
93 , mSize(size) {
94 }
95
~LUTInterpolator()96 LUTInterpolator::~LUTInterpolator() {
97 }
98
interpolate(float input)99 float LUTInterpolator::interpolate(float input) {
100 float lutpos = input * mSize;
101 if (lutpos >= (mSize - 1)) {
102 return mValues[mSize - 1];
103 }
104
105 float ipart, weight;
106 weight = modff(lutpos, &ipart);
107
108 int i1 = (int) ipart;
109 int i2 = MathUtils::min(i1 + 1, (int) mSize - 1);
110
111 LOG_ALWAYS_FATAL_IF(i1 < 0 || i2 < 0, "negatives in interpolation!"
112 " i1=%d, i2=%d, input=%f, lutpos=%f, size=%zu, values=%p, ipart=%f, weight=%f",
113 i1, i2, input, lutpos, mSize, mValues.get(), ipart, weight);
114
115 float v1 = mValues[i1];
116 float v2 = mValues[i2];
117
118 return MathUtils::lerp(v1, v2, weight);
119 }
120
121
122 } /* namespace uirenderer */
123 } /* namespace android */
124